Vaxxers

How do you create a life-saving vaccine under the pressure of a global pandemic? In Vaxxers, Sarah Gilbert and Catherine Green reveal how Oxford scientists compressed a decade of vaccine development into a matter of months. Their story spans the technical, logistical and moral dimensions of science in crisis — from the lab benches of the Jenner Institute to the world’s largest manufacturing lines.

At its heart, the book argues that rapid action during COVID‑19 was not a miracle—it was the payoff from years of steady investment in platform technologies, flexible funding, and determined people who refused to wait for bureaucracy to catch up. Oxford’s ChAdOx1 vaccine became possible because the team had already prepared the building blocks for emergencies long before SARS-CoV‑2 appeared.

From Preparation to Pandemic

Years before 2020, Sarah Gilbert’s group had been refining the chimpanzee adenovirus vector (ChAdOx1), a safe, non-replicating viral platform. Its modularity meant you only needed to swap a gene, not reinvent the vehicle. Lessons from Ebola, MERS, and influenza prepared them for “Disease X,” a placeholder name the WHO used for an unknown future threat. Critics saw this as speculative research; in 2020, it proved prophetic.

Institutions like CEPI, the Coalition for Epidemic Preparedness Innovations, were founded to fund exactly this kind of pre-pandemic work, though even Oxford’s early funding proposals were sometimes rejected. The pandemic exposed how vital risk-taking funding is when global safety depends on preparation rather than reaction.

From Gene to Vial

Once Chinese scientists published the viral genome in January 2020, the Oxford team had what they needed to act. They encoded the spike protein, inserted it into the adenovirus backbone, and began growing vaccine material in HEK293 cells. They faced a fundamental choice: take a rapid route that risked technical failure, or a classic process that risked lost time. They hedged, running both simultaneously — a decision that saved weeks when one method failed and the other succeeded.

Through iterative steps—production, purification, filling, labeling, and testing—the vaccine transformed from a DNA slip in a Jiffy bag to millions of sterile vials. Alongside this technical sprint came the human effort of technicians like Ioana Baleanu filling vials by hand, and logistical feats such as chartered flights when international shipping ground to a halt.

Trials and Trust

Clinical trials unfolded in overlapping phases led by Andy Pollard and the Oxford Vaccine Group. Volunteers came forward by the thousands. Every sample had to be processed within hours, every event logged and classified. When Suspected Unexpected Serious Adverse Reactions (SUSARs) occurred, trials paused for investigation—not scandal, but standard safety procedure. The media, however, often turned these pauses into drama, amplifying misunderstanding.

Despite trial challenges — varying dose sizes, differing manufacturing sites and assay methods — real-world data confirmed robust effectiveness. The vaccine reduced hospitalisation by over 90% after one dose in Scotland, proving that practical impact outweighed headline comparisons with mRNA vaccines.

Partnership, Scale, and Public Responsibility

None of this could have succeeded without funding “at risk.” Oxford began manufacture before guaranteed grants arrived, relying on CEPI and later the UK Vaccines Taskforce. Partnerships turned an academic breakthrough into a global solution: AstraZeneca supplied scale and infrastructure; Advent in Italy and Serum Institute of India produced at industrial volumes. AstraZeneca’s pledge for not‑for‑profit pricing during the pandemic reflected Oxford’s aim to create a vaccine for the world.

Communication became the final battlefield. Conspiracies, misinformation, and distrust—rooted in both historical abuses and modern misinformation—threatened progress. Cath Green’s direct engagement with the public, explaining simply how she made the vaccine, embodied the antidote: empathy and transparency. In their storytelling, Gilbert and Green argue that vaccine confidence depends on honest voices as much as on scientific validation.

What Comes Next

As variants like B.1.1.7 and B.1.351 emerged, the same ChAdOx1 chassis enabled rapid updates. The underlying message is timeless: technological tools matter, but institutions and values turn them into protection. Preparedness means investing before the crisis, maintaining flexible systems for trial and regulation, and ensuring global equity when disease does not respect borders.

Core idea

Scientific speed comes from preparation, partnership, and public trust — all built long before the emergency. The Oxford story shows that the next Disease X is inevitable, but being ready for it is a deliberate choice, not a miracle.

A scientific platform is like a reusable engine that transforms vaccine development from invention to adaptation. Sarah Gilbert’s ChAdOx1 platform used a harmless chimpanzee adenovirus vector that could deliver any chosen gene. When new pathogens appear, you can replace a single component — the gene coding for a target protein — instead of redesigning the entire system.

Because ChAdOx1 had already been tested against viruses like MERS and influenza, Oxford entered 2020 with years of accumulated data: manufacturing behavior, safety profiles, and regulatory familiarity. This institutional memory condensed months of trial-and-error into pre-existing procedures.

Lessons from Ebola and the Birth of CEPI

The slow response to Ebola exposed global unpreparedness. In reaction, WHO listed “Disease X” and CEPI was founded in 2017 to finance rapid-response platforms. Oxford’s early unsuccessful CEPI proposal ironically foreshadowed the pandemic that would prove their concept essential. The takeaway is sharp: technology readiness must be paired with sustained political and financial commitment.

Without pre-funded, validated methods—qualified cell banks, preapproved assays, and stable manufacturing—platform science is theoretical. Gilbert’s persistence ensured these foundations existed when SARS-CoV‑2 appeared.

Key takeaway

Preparedness is the art of doing science before you know which crisis it will solve.

Developing a vaccine fast means navigating trade-offs between speed and certainty. Oxford’s team coined the distinction between the rapid method — using pre-built adenoviral backbones — and the classic method — building everything from scratch. Each approach carries different types of risk: technical versus temporal.

The Rapid Route

The rapid route saved weeks by starting with pre-prepared vaccine chassis from Vaccitech. Yet technical instability meant early attempts failed, wasting effort but not compromising safety. This “at-risk” work paid dividends later; it revealed where reliability broke down and forced a robust fallback plan.

The Classic-Plus Compromise

When rapid production faltered, Oxford implemented a hybrid called classic-plus: cloning from single infected cells combined with next-generation sequencing. Within 24 hours, sequencing confirmed which clones matched the intended design. This innovation produced the D8 clone that seeded all later manufacturing.

Lesson

The Oxford experience shows that accelerating science safely depends on parallel thinking: run multiple paths, track data quickly, and invest in quality-control technologies that make risk-taking manageable.

Manufacturing a viral-vectored vaccine is more choreography than artistry. It involves five precise steps — making starter material, producing bulk vaccine, purifying, filling, and testing — each a potential bottleneck. You see a transformation from microvolumes of liquid in a biosafety cabinet to massive industrial batches filling millions of vials.

Scaling the Process

Oxford’s Clinical Biomanufacturing Facility (CBF) worked at 10-litre scale while partners like Advent in Italy handled 100-litre runs and commercial sites exceeded 1,000 litres. Technicians worked under intense constraints—sterility, documentation, and courier logistics—each break in the chain risking months of delay. Quality checks by the MHRA and the Qualified Person (Richard Tarrant) were the last safeguard before human clinical use.

Industrial partners such as Pall and Oxford BioMedica tested improved yield processes. Adjustments in culture medium magnified output fivefold at one stage. These technical optimisations bridged the gap between academic and commercial production, enabling billions of global doses.

Insight

Science gets headlines, but manufacturing quality and logistics determine whether discoveries reach the public.

Speed without financing is wishful thinking. Oxford’s journey demonstrates how flexible, risk-tolerant investment bridges the infamous 'valley of death.' Early programs like VaxHub supported prototype work; CEPI and the UK Vaccines Taskforce later provided the capital to scale manufacturing “at risk.” Oxford signed production contracts before formal funding arrived, gambling institutional funds against time.

A Global Manufacturing Network

When AstraZeneca partnered in April 2020, the project gained industrial power. Advent (Italy), Pall, Oxford BioMedica, Serum Institute of India, and SK Bio built a distributed manufacturing web to guarantee supply to multiple continents. Oxford’s insistence on equitable pricing shaped their agreements: AstraZeneca promised pandemic-period not-for-profit pricing and indefinite low-cost supply for lower-income nations.

The partnerships also embodied ethical balancing: ensuring global fairness while withstanding political scrutiny and supply disputes, particularly within Europe. Public trust depended on transparency, not secrecy.

Principle

Preparedness is not just about labs — it’s about networks of trust between scientists, governments, and manufacturers willing to act before certainty exists.

Oxford’s clinical program compressed the usual decade-long sequence of stages into a continuous wave. Phases I–III overlapped, and every stage had dual goals: maintain robust safety while racing to collect enough infection data to measure efficacy.

Trial Design Under Pressure

Starting in April 2020, the first volunteers received doses under meticulous observation. Older participants were added in later waves after safety confirmation. Each blood sample demanded rapid processing — often late-night lab shifts ensured viable assays. The data revealed strong immune responses across age groups and justified moving to large-scale trials in Brazil and South Africa where case numbers were higher.

Safety Surveillance and Regulation

Every volunteer’s symptom, no matter how trivial, was recorded. When serious adverse events required a pause, regulators investigated fully before approving restarts. Later, rare clotting events among millions of vaccinated people tested regulators’ ability to balance minute risks against massive benefits. The MHRA’s transparent approach—explaining decisions publicly—helped preserve confidence in the process.

Essential insight

In emergency science, integrity is the only currency. Pausing, investigating, and communicating uncertainties are not delays—they are ethical symmetry with the trust volunteers place in research.

During the pandemic, information spread as fast as the virus itself. Oxford’s scientists learned that the success of vaccination depended on fighting misinformation as much as infection. Cath Green and Sarah Gilbert faced rumours, premature media leaks, and politicised narratives while still running labs.

Bridging Science and the Public

A memorable exchange at a pizza van—Green explaining to a skeptical woman that she herself made the vaccine—captures the power of humanising science. Transparency, empathy, and clear explanation proved stronger than fear. The Science Media Centre helped coordinate consistent, factual messaging to counter disinformation about ingredients, fertility, or ethics of HEK293 cells.

Media, Misunderstanding, and Reputation

Leaks and half-understood efficacy numbers created confusion (especially over “half-dose” subgroups). But by publishing detailed Lancet papers alongside accessible outreach, the team reclaimed narrative control. Public engagement became a second front of public health, showing that communication strategy must accompany scientific achievement.

Core idea

Trust is built in conversation, not in press releases. The Oxford team’s openness turned skepticism into connection and set a model for future crisis communication.

The story closes by looking forward. Variants from Kent, South Africa, and Brazil showed that viral evolution is inevitable. But platform technologies transform this threat into an engineering problem rather than a crisis. When a new spike variant appears, you can swap the genetic insert and re‑start production within weeks — not years.

Continuous Improvement and Global Investment

In February 2021, Oxford began variant‑specific updates using streamlined rapid methods. These efforts underscored a broader principle: preparedness is cultural and infrastructural. Countries must invest in regional bio‑manufacturing (VMIC in the UK is one such model), harmonised regulation, and standing trial networks ready to deploy when Disease Y emerges.

Ultimately the authors argue that no nation is safe until all are. Equitable vaccine distribution through Covax and dose reallocation isn’t altruism—it’s strategy. Global connectivity makes fairness a public‑health necessity.

Final message

Scientific agility exists — but only cooperation, funding, and foresight turn potential into protection.